It is a spin-off of Samurai Warriors 4, part of the Samurai Warriors series, which in turn is a spin-off of the long-running Dynasty Warriors series, both of which are also hack and slash games. Source: Wikipedia, "[en.wikipedia.org/wiki/Samurai_Warriors%3A_Sanada_Maru Samurai Warriors: Sanada Maru]", available under the CC-BY-SA License.